Lindholm is signed for another year, which is why he's coming back. When his contract is up, i suspect they'll move on from him too.
These are 4th liners and highly replaceable.
I understand why Nordstrom has been moved on, but I disagree with the basic principle that 4th liners are 'highly replaceable'. Of course there are more of them and they're more interchangeable than top 6 forwards, but you still need to get your combos and balance right in who you select to play on your 4th, not just for the sake of that line, but for the culture of the whole team, and often your PK. In fact I'd argue that their impact is often more significant than that of your 3rd line guys, since they'll frequently get more minutes, have a greater defensive responsibility, and are more likely to be PKers.
The Bruins 4th was worse last season without Acciari, and while I'm not going to delve into the PK stats, at the very least it left the team with one less very reliable penalty killer to call upon. Without Nordstrom, it will decline still further unless other guys step up and bring the same hustle, sand and defensive nous, and find the same chemistry that Kuraly, Wags, Noel and Nords had at their best. I'm not arguing that either of the latter should have been retained - Acciari at the very least priced himself out of Boston - what I'm saying is that when you move capable 4th liners on there are still consequences and you can't just plug in the next guy and expect to just carry on exactly as before.